/*
 *  RFC 1186/1320 compliant MD4 implementation
 *
 *  Based on XySSL: Copyright (C) 2006-2008  Christophe Devine
 *
 *  Copyright (C) 2009  Paul Bakker <polarssl_maintainer at polarssl dot org>
 *
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *    * Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *    * Neither the names of PolarSSL or XySSL nor the names of its contributors
 *      may be used to endorse or promote products derived from this software
 *      without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 *  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*
 *  The MD4 algorithm was designed by Ron Rivest in 1990.
 *
 *  http://www.ietf.org/rfc/rfc1186.txt
 *  http://www.ietf.org/rfc/rfc1320.txt
 */

#include "netif/ppp/ppp_opts.h"
#if PPP_SUPPORT && LWIP_INCLUDED_POLARSSL_MD4

#include "netif/ppp/polarssl/md4.h"

#include <string.h>

/*
 * 32-bit integer manipulation macros (little endian)
 */
#ifndef GET_ULONG_LE
#define GET_ULONG_LE(n, b, i)                                                  \
  {                                                                            \
    (n) = ((unsigned long)(b)[(i)]) | ((unsigned long)(b)[(i) + 1] << 8) |     \
          ((unsigned long)(b)[(i) + 2] << 16) |                                \
          ((unsigned long)(b)[(i) + 3] << 24);                                 \
  }
#endif

#ifndef PUT_ULONG_LE
#define PUT_ULONG_LE(n, b, i)                                                  \
  {                                                                            \
    (b)[(i)] = (unsigned char)((n));                                           \
    (b)[(i) + 1] = (unsigned char)((n) >> 8);                                  \
    (b)[(i) + 2] = (unsigned char)((n) >> 16);                                 \
    (b)[(i) + 3] = (unsigned char)((n) >> 24);                                 \
  }
#endif

/*
 * MD4 context setup
 */
void md4_starts(md4_context *ctx) {
  ctx->total[0] = 0;
  ctx->total[1] = 0;

  ctx->state[0] = 0x67452301;
  ctx->state[1] = 0xEFCDAB89;
  ctx->state[2] = 0x98BADCFE;
  ctx->state[3] = 0x10325476;
}

static void md4_process(md4_context *ctx, const unsigned char data[64]) {
  unsigned long X[16], A, B, C, D;

  GET_ULONG_LE(X[0], data, 0);
  GET_ULONG_LE(X[1], data, 4);
  GET_ULONG_LE(X[2], data, 8);
  GET_ULONG_LE(X[3], data, 12);
  GET_ULONG_LE(X[4], data, 16);
  GET_ULONG_LE(X[5], data, 20);
  GET_ULONG_LE(X[6], data, 24);
  GET_ULONG_LE(X[7], data, 28);
  GET_ULONG_LE(X[8], data, 32);
  GET_ULONG_LE(X[9], data, 36);
  GET_ULONG_LE(X[10], data, 40);
  GET_ULONG_LE(X[11], data, 44);
  GET_ULONG_LE(X[12], data, 48);
  GET_ULONG_LE(X[13], data, 52);
  GET_ULONG_LE(X[14], data, 56);
  GET_ULONG_LE(X[15], data, 60);

#define S(x, n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))

  A = ctx->state[0];
  B = ctx->state[1];
  C = ctx->state[2];
  D = ctx->state[3];

#define F(x, y, z) ((x & y) | ((~x) & z))
#define P(a, b, c, d, x, s)                                                    \
  {                                                                            \
    a += F(b, c, d) + x;                                                       \
    a = S(a, s);                                                               \
  }

  P(A, B, C, D, X[0], 3);
  P(D, A, B, C, X[1], 7);
  P(C, D, A, B, X[2], 11);
  P(B, C, D, A, X[3], 19);
  P(A, B, C, D, X[4], 3);
  P(D, A, B, C, X[5], 7);
  P(C, D, A, B, X[6], 11);
  P(B, C, D, A, X[7], 19);
  P(A, B, C, D, X[8], 3);
  P(D, A, B, C, X[9], 7);
  P(C, D, A, B, X[10], 11);
  P(B, C, D, A, X[11], 19);
  P(A, B, C, D, X[12], 3);
  P(D, A, B, C, X[13], 7);
  P(C, D, A, B, X[14], 11);
  P(B, C, D, A, X[15], 19);

#undef P
#undef F

#define F(x, y, z) ((x & y) | (x & z) | (y & z))
#define P(a, b, c, d, x, s)                                                    \
  {                                                                            \
    a += F(b, c, d) + x + 0x5A827999;                                          \
    a = S(a, s);                                                               \
  }

  P(A, B, C, D, X[0], 3);
  P(D, A, B, C, X[4], 5);
  P(C, D, A, B, X[8], 9);
  P(B, C, D, A, X[12], 13);
  P(A, B, C, D, X[1], 3);
  P(D, A, B, C, X[5], 5);
  P(C, D, A, B, X[9], 9);
  P(B, C, D, A, X[13], 13);
  P(A, B, C, D, X[2], 3);
  P(D, A, B, C, X[6], 5);
  P(C, D, A, B, X[10], 9);
  P(B, C, D, A, X[14], 13);
  P(A, B, C, D, X[3], 3);
  P(D, A, B, C, X[7], 5);
  P(C, D, A, B, X[11], 9);
  P(B, C, D, A, X[15], 13);

#undef P
#undef F

#define F(x, y, z) (x ^ y ^ z)
#define P(a, b, c, d, x, s)                                                    \
  {                                                                            \
    a += F(b, c, d) + x + 0x6ED9EBA1;                                          \
    a = S(a, s);                                                               \
  }

  P(A, B, C, D, X[0], 3);
  P(D, A, B, C, X[8], 9);
  P(C, D, A, B, X[4], 11);
  P(B, C, D, A, X[12], 15);
  P(A, B, C, D, X[2], 3);
  P(D, A, B, C, X[10], 9);
  P(C, D, A, B, X[6], 11);
  P(B, C, D, A, X[14], 15);
  P(A, B, C, D, X[1], 3);
  P(D, A, B, C, X[9], 9);
  P(C, D, A, B, X[5], 11);
  P(B, C, D, A, X[13], 15);
  P(A, B, C, D, X[3], 3);
  P(D, A, B, C, X[11], 9);
  P(C, D, A, B, X[7], 11);
  P(B, C, D, A, X[15], 15);

#undef F
#undef P

  ctx->state[0] += A;
  ctx->state[1] += B;
  ctx->state[2] += C;
  ctx->state[3] += D;
}

/*
 * MD4 process buffer
 */
void md4_update(md4_context *ctx, const unsigned char *input, int ilen) {
  int fill;
  unsigned long left;

  if (ilen <= 0)
    return;

  left = ctx->total[0] & 0x3F;
  fill = 64 - left;

  ctx->total[0] += ilen;
  ctx->total[0] &= 0xFFFFFFFF;

  if (ctx->total[0] < (unsigned long)ilen)
    ctx->total[1]++;

  if (left && ilen >= fill) {
    MEMCPY((void *)(ctx->buffer + left), input, fill);
    md4_process(ctx, ctx->buffer);
    input += fill;
    ilen -= fill;
    left = 0;
  }

  while (ilen >= 64) {
    md4_process(ctx, input);
    input += 64;
    ilen -= 64;
  }

  if (ilen > 0) {
    MEMCPY((void *)(ctx->buffer + left), input, ilen);
  }
}

static const unsigned char md4_padding[64] = {
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

/*
 * MD4 final digest
 */
void md4_finish(md4_context *ctx, unsigned char output[16]) {
  unsigned long last, padn;
  unsigned long high, low;
  unsigned char msglen[8];

  high = (ctx->total[0] >> 29) | (ctx->total[1] << 3);
  low = (ctx->total[0] << 3);

  PUT_ULONG_LE(low, msglen, 0);
  PUT_ULONG_LE(high, msglen, 4);

  last = ctx->total[0] & 0x3F;
  padn = (last < 56) ? (56 - last) : (120 - last);

  md4_update(ctx, md4_padding, padn);
  md4_update(ctx, msglen, 8);

  PUT_ULONG_LE(ctx->state[0], output, 0);
  PUT_ULONG_LE(ctx->state[1], output, 4);
  PUT_ULONG_LE(ctx->state[2], output, 8);
  PUT_ULONG_LE(ctx->state[3], output, 12);
}

/*
 * output = MD4( input buffer )
 */
void md4(unsigned char *input, int ilen, unsigned char output[16]) {
  md4_context ctx;

  md4_starts(&ctx);
  md4_update(&ctx, input, ilen);
  md4_finish(&ctx, output);
}

#endif /* PPP_SUPPORT && LWIP_INCLUDED_POLARSSL_MD4 */
